Article for use in an electrical switch device or in a thermostatically-controlled mechanism



Jan. 17, 1961 c. SAGONA 2,968,708

ARTICLE FOR USE IN AN ELECTRICAL SWITCH DEVICE OR IN ATHERMOSTATICALLY-CONTROLLED MECHANISM Filed Nov. 28. 1956 2 Sheets-Sheet1 I PM 5 iam mm \5 I c I 2.6 l HIHIHHI HIHIHHH 1.1m

25 \t 26 as (Tmmuzs SAQQNA,

INVENTOR.

Aim-0mm- Jan. 17, 1961 c 5 G NA 2,968,708

A 0 ARTICLE FOR USE IN AN ELECTRICAL SWITCH DEVICE OR IN ATHERMOSTATICALLY-CONTROLLED MECHANISM Filed Nov. 28. 1956 2 Sheets-Sheet2 Fm Z #5 J? CH/IELESSAGONA,

INVENTOR ATTO/Q. NEH.

United States Patent ARTICLE FOR USE IN AN ELECTRICAL SWITCH DEVICE ORIN A THERMOSTATICALLY-CON- TROLLED MECHANISM Charles Sagona, 73 Bay 34thSt., Brooklyn, N.Y.

Filed Nov. 28, 1956, Ser. No. 624,901

1 Claim. (Cl. 200-413) The present invention relates to devicesadaptable in constructions of electrical switches, micro-switches,relays, circuit breakers and in various thermostat mechanisms. These arestated as particular examples ofits use.

An object of this invention is to provide a novel and improved deviceemploying a blade spring which operates with a rapid snap action makingit suitable in the types of apparatus mentioned.

Another object is to provide a novel and improved device of thecharacter described, whose blade spring member is actuated by a new modeof operation.v

A further object is to provide a novel and improved device of the classset forth, in which a minimum of operating movement will cause asubstantial shift in the blade spring member.

Still a further object is to provide a novel and improved device of thekind mentioned, which is simple in construction, cheap to manufactureand which is efiicient in carrying out the purposes for which it isdesigned.

Other objects and advantages will become apparent as this disclosureproceeds.

For the practice of this invention, it is essential to have a frame onwhich a blade spring is so mounted that the ends of such blade springare free for relative movement towards each other. In some embodiments,the blade spring in initial rest position, is straight, in others, bent.In still other embodiments, the blade spring is initially bowed and ismounted to be straight in normal rest position on the frame, or elsebowed in the opposite direction, all of which will be shown andexplained. In all embodiments, the device is made to operate by causinga change in the distance between the ends of the blade spring, by actionand reaction acting at such ends. This is effected by application of aphysical force or the creation of the equivalently acting forces causedby heat transference. Spring blade end movement may be caused byexpansion or contraction of the spring per se or the frame. member ortheir relative expansion or contraction when subjected to a hot or coldenvironment as the case may be. Expansion of the blade spring may beeffected by having it heated by an electric current. Regardless of themanner of causing force to deform the blade spring from its normal restposition, the gist of this invention remains the same.

I will now proceed with a more detailed description of various formsthis invention may assume and the various manners in which such devicesare operated and used. Of course, the specific embodiments illustratedand de scribed are to be deemed mere examples of the practice of thisinvention.

In the accompanying drawings forming part of this specification, similarcharacters of reference indicate corresponding parts in all the views.

Fig. 1 is a front view of a preferred embodiment of this invention whichwill be shown can operate either as a micro-switch or as a thermostatcontrol. Considered as a switch, it is here shown in condition when theoperating button is pressed. Considered as a thermostat, the buttonbeing omitted, the device is here shown when the heated environment hasreached a predetermined temperature- In this view, part of acoverplateisbroken away to expose the mechanism.

Fig. 2 is a top plan view of Fig. 1.

Fig. 3 is a section taken at lines 3-3 in Fig. 2'.

Fig. 4 is a section taken at lines 44 in Fig. 1.

Fig. 5 shows the blade spring in its unmounted condition. This view istaken of a longitudinal edge of said blade spring.

Fig. 6 is a side view of Fig. 5, showing a face of said blade spring.

Fig. 7 is a'view like Fig. 1, but of a modified embodiment; the bladespring being shown herein normal at rest position.

Fig. 8 is a similar view of another modified embodiment.

Fig. 9 is a similar view of another modified embodie ment.

. Fig. 10 shows the device of Fig. 9 set in a different initialcondition.

In the drawings showing preferred embodiments of this invention, thenumeral 15 designates generally a dielectric frame presenting anelongated straight wall 16 on one of its members, against which theinitially convex face 17' of a bowed blade spring 17 rests straightenedthereagainst andof course is therebycaused to be in flexed condition.Said blade spring isso held by having its ends anchored, one end to. theframe and its other end in an operating button 18. .The attachment toframe may be in a diametral V-notch in the head of the shankaof a headedan:- cho rage button l9iwhich is held tightly in a counterbored hole inthe frame body by a screw 20 which is threadedly engaged in thebushing-21 as shown in Fig. 3. The other end of'the blade spring 17setsinto a similar. and aligned V-notch in the head end of the invertedoperating button 18 whose shank extends from the frame throughthebushing 22, in which bushing said shank is slidable towards theanchorage button 19.

When the operating button 18 is pressed so that'it moveseven slightly,it will cause the blade spring 17 to become bowed and rapidly snap awayfrom the'wall 16 because said blade spring can go nowhere else. From thenormal rest position shown in Fig. 3, the blade spring 17 willautomatically assume the condition shown in Fig. l, where the bladespring has been so bowed that its face 17" which when said blade springwas unmountedv was concave, is now convex.

The blade spring 17 at its mid-section may carry the contact points 24,25. To have a switch devicewhich is normally open, but ismade to assumeclosed condition upon pressing the operating button 18, the framecarriesthe contact point 24' in the path of movement of the blade spring 17 andnormally spaced from the contact point 24 on the blade spring as in Fig.3.

To have a switch device which is normally closed, but is made to assumeopen condition upon pressingthe operating button 18, the frame hasmounted thereon the .contact point 25 so that at normal rest position of.the

blade spring, contacts 25 and 2S touch.

The contact points 24', 25 may be at the end of: the screws 26, 27respectively. These screws are threadedly engaged by the frame to serveas binding postsfor electrical connections. Screw 20, of course, alsoservesas a terminal for electrical connection to the circuit the switchis to control. Each of .the mentioned screws may have a lock nut as at28 to fix the screws in any set position as adjustment. may require; anda second. nut as at 29 to secure wire connections.

It is advisable that the wall 16 extend substantially theqentire lengthof the blade spring.17 so that upon pressing theoperating button, theblade spring can move nowhere but away from such stop wall;

The blade spring is preferably of spring copper alloy and the frame maybe of Bakelite, plastic, a ceramic or other suitable insulativematerial. In practical constructions for commercial use, the devicewould be about half the size shown. This is stated as mere suggestion inview of a working specimen which was so made. A cover plate 30 may beprovided as shown in Figs. 1 and 2.

The device, even as illustrated, may be used as a thermostat, though theoperating button in such instance is unnecessary. When in condition asshown in Fig. 3, the straightened spring 17 must be incapable of anylongitudinal movement with respect to the frame 15. Since the screw 20is stationary and the operating button 18 is stopped by the bushing 22,the required situation exists. When the blade spring 17 is subjected toa heat environment, the ensuing expansion thereof will cause a force toact on the blade spring effecting its snap movement to the positionshown in Fig. 1. What actually occurs is that when the blade springexpands, it tends to lengthen. But increase in the distance between theends of said blade spring is impossible. Hence there is a resultingforce holding the blade springs ends apart less than such ends would beif they were free. This is the equivalent of applying a force to shortenthe distance between the said ends and the device is made to assume thecondition as in Fig. 1. Of course, when the device is so used as athermostat, the material of the frame should be of the nature that haspractically no expansion when subjected to heat. It may be noted, thatwhen the embodiment is for thermostat use, the anchorage for each of theends of the blade spring 17, may be as that anchoring its lower endinFig. 3. Such construction is shown in Fig. 9.

Inaddition to being used as a thermostat, each of the embodiments shownin Figs. 3 and 9 may also be used as a relay or as a circuit breakerwhen so interposed in a circuit that an electric current is made to passthrough the blade spring to heat same upon attainment of a certaindegree of heat, the blade spring in either instance will expand. Suchexpansion will cause either of said blade springs 17 or 31 toautomatically assume the positions shown in Figs. 1 and respectively. Asa circuit breaker, the blade spring movement will cause a break in thecircuit in which the contact points 25, 25' are interposed as a switch.As a relay, such blade spring movement may be used either to cause abreak in the circuit as explained, or to close a circuit in which thecontact points 24, 24 are interposed as a switch, or both suchincidents, depending upon the switch functions required. To adjust forthe temperature the devices are to operate adjustment is made bydifferent settings of the screw 20. Movement of such screw to loosen theblade spring in either device of Figs. 3 and 9 would cause blade springshift .to that of Fig. 1 and Fig. 10 respectively at a higher incrementof temperature.

The devices shown in Figs 3 and 9 may also be used for thermostatcontrol where expansion and contraction of the frame is relied upon foroperation. Of course in such instances, the material of the frame or 35shall have an appreciably greater coefiicient of expansion than that ofthe associated blade spring. In such arrangement, the device in initialcondition as shown in Fig. 9 may serve as a thermostat in coldenvironment. When the temperature of such environment falls to a certaintemperature, the frame will contract and automatically the blade springwill assume the position shown in Fig. 10. If then the temperature ofsuch environment shall rise to a certain degree, the frame will expandand the blade spring will automatically return to the position shown inFig. 9. In such arrangement, the device in initial condition as shown inFig. 10 may serve as a thermostat in a hot environment. When the heat ofsuch environment rises to a certain temperature, the frame will expandand automatically the blade spring will assume the position shown inFig. -9. If then the temperature of such environment shall fall to acertain degree, the frame will contract and the blade spring willautomatically return to the position shown in Fig. 10.

Whereas the blade springs 17, 31 and 40 are electrically conductive, theblade spring 33 in the embodiment shown in Fig. 8 is of dielectricmaterial. Hence such blade spring carries a contact button 34 to makesimultaneous contact with the fixed contact points 38 and 39 toconstitute a switch means.

In the embodiment shown in Fig. 7, the blade spring 4t. stands in spaceand is straight as it was in unmounted position. Pressing the button 41,or a contraction of its frame 42, would cause such blade spring to bendeither to the right or to the left. Hence to serve as a switch means,such blade spring in the embodiment shown is electrically conductive andthe contact points which are at either side thereof respectively wouldneed be in electrical connection. In this embodiment, there is no rapidsnap action. The blade springs of all the other embodiments may also bestraight when unmounted, if rapid snap action is not required. Being upagainst a stop wall as 16, they could only move away from it when theends of such blades are brought closer either by pushing of button 18,contraction of frame or expansion of such blade spring, as have beenexplained. It might also be noted that blade spring 40 may be set to bea bit bowed. For such, spring 17 may be used. When this is so, uponpressing the button 41, the convex face 17 will become more convex andthen only one contact point at 44 would be required to complete a switchdevice.

As one example of an electrical circuit, reference is bad to Fig. 9where a current supply 45 is controlled by a manual switch 46 to causethe blade spring 31 to become heated. Upon expansion of such bladespring, it will close the circuit of any electrically-operated apparatus47, included as shown. To those versed in the electrical art, the manyuses of the devices illustrated and appropriate circuits therefor willbe apparent without further illustration.

Where the blade spring needs to be electrically cond-uctive, it issuggested that it be of a copper alloy as for instance beryllium copperand where it may be nonconductive, same could be of a suitable plasticas nylon. In embodiments which rely on expansion and retraction of theframe for operation, the frame may be made of such materials as Bakeliteand the blade spring of Invar steel.

This invention is capable of numerous forms and various applicationswithout departing from the essential features herein disclosed. It istherefore intended and desired that the embodiments shown herein bedeemed illustrative and not restrictive and that the patent shall coverall patentable novelty herein set forth; reference being had to thefollowing claim rather than to the specific description herein toindicate the scope of this invention.

I claim:

In an article for use in an electrical switch device or in athermostatically controlled mechanism of the character described, thecombination of a frame, a stop member thereon, a blade spring of adielectric material held at its ends on said frame; said blade springbeing in bowed condition before being mounted on the frame; said bladespring being positioned in straight condition with its initially convexsurface against such stop member whereby said blade spring is in flexedcondition; said stop member maintaining the major portion of said bladespring against movement in the direction towards said stop member; saidspring being free to bend away from said stop member and then back againto be against said stop member means to impart a force to at least oneend of said blade spring in a direction substantially along the linebetween said ends to' shorten the distance between said ends, whereuponthe blade spring will automatically bend away from said stop member, afirst electrically conductive element carried on said blade spring and apair of spaced electrically conductive elements carried on the frame andelectrically insulated from each other, whereby said pair of elementsare in contact with said first element only at one position of the bladespring.

References Cited in the file of this patent UNITED STATES PATENTS 6Vaughn Aug. 15, 1933 Mason July 5, 1938 Klahn Aug. 23, 1938 Gent Mar. 4,1941 Platz Sept. 9, 1941 Henry Jan. 31, 1950 Brown Nov. 10, 1953 Immelet al Mar. 30, 1954 Schwaneke June 11, 1957 OTHER REFERENCES

